This invention relates to the froth flotation of ores and in particular to the froth flotation of molybdenum containing ores.
Froth flotation procedures for the recovery of desired minerals from ores containing the same have been employed for many years. Froth flotation operates to separate finely ground valuable minerals from their associated gangue. In general, the frothing process is carried out by introducing air into a pulp of finely divided ore in water containing a frothing or foaming agent whereby a froth is formed. The minerals with a specific affinity for air bubbles rise to the surface in the froth and are thus separated from the gangue wetted by water.
Typically, the flotation process consists of crushing the mineral containing ore; contacting the resulting finely ground mixtures of particles of mineral and gangue with flotation agents, frothing agents and other additives; contacting the treated mineral particles with air bubbles to buoy or lift the mineral to the surface and recovering the desired metal from the resulting froth.
Froth flotation is the principal means of concentrating copper, lead, molybdenum, phosphate, zinc, potash ores and numerous other minerals. In the case of recovering molybdenum, upon which the present invention is particularly focused, it is well known that a significant portion of the world supply of molybdenum is recovered as a by-product of copper mining, namely molybdenite, MoS.sub.2. Copper mining operations produce, as a by-product, a concentrate containing copper and molybdenum (as molybdenite) and typically the molybdenite is separated from the copper by froth flotation as generally described hereinbefore.
U.S. Pat. Nos. 4,347,126 and 4,347,127 disclose apparatus and methods for the froth flotation of coal and other particulate mineral matter. In accordance with the method of froth flotation disclosed in said U.S. Pat. Nos. 4,347,126 and 4,347,127, an input slurry of particulate matter is sprayed under pressure through a spray nozzle into a flotation cell so that the particulate matter is dispersed through an aeration zone into the liquid surface in the cell to create a froth on the liquid surface in which a quantity of the desired particulate matter is floating.
It has now been found that utilization of the teachings of said U.S. Pat. Nos. 4,347,126 and 4,347,127 to recover and beneficiate molybdenite from bulk molybdenite concentrate containing impurities including copper, results in a significant improvement over conventional flotation procedures used for recovering molybdenite.